The lens of a camera has a great impact on the ability of the camera to capture images. More specifically, the camera lens affects the zoom capabilities of the camera as well as the sharpness and resolution of the resulting image. For a traditional camera, the lens is often designed to focus the light received through the lens on the image sensor.
Lens design for light-field cameras is significantly different than for a traditional camera. The resolving power of a traditional camera is a function of its lens and the sensor. In order for the lens to not limit the resolving power of the system, the focus spot size of the lens must be equal to or smaller than the grain size of the film or the pixel size of the detector over the full size of the image plane.
By contrast, the resolving power of a light-field camera is dependent on a multitude of factors including, for example, the main lens, where the main lens is focused, the microlens array, the sensor's pixel size, and the sensor's pixel angular sensitivity. Optimization of lenses for light-field cameras thus presents unique challenges: In many cases, an optimized main lens for a light-field camera is not necessarily one which produces the smallest possible spot size.